Egypt has the oldest continuously existing civilization in the world. Most scholars believe that the Egypt was first unified in about 3100 BC. Egypt maintained its independence and unity for many centuries thereafter. It suffered disunity now and then and experienced brief periods of foreign domination—by the Hyksos in the 17th and 16th centuries BC, the Assyrians in the 7th century BC, and the Persians in the 6th and 5th centuries BC—before the arrival of Macedonian conqueror Alexander the Great in 332 BC. Alexander made Egypt a part of his vast empire.
Alexander’s empire broke up after his death in 323 BC. One of his generals, Ptolemy, became ruler of Egypt, and in 305 BC he assumed the title of king. Ptolemy founded the Ptolemaic dynasty. Under these rulers, Egypt became a centre of the Hellenistic world—that is, the vast region, encompassing the eastern Mediterranean basin and the Middle East, in which Greek culture and learning were pre-eminent from Alexander’s conquest until the 1st century BC. Although the Ptolemies preserved many native traditions, they remained unpopular because they kept Egyptians from important governmental posts.
The Romans conquered Egypt in 30 BC, ruling it as a province of their empire for the next several centuries. One of the first countries to be exposed to Christianity, Egypt became predominantly Christian by the end of the 3rd century ad. In 395, when the Roman Empire was divided, Egypt was included in the Eastern Roman Empire, later called the Byzantine Empire. By the 5th century a bitter religious dispute over the nature of Christ, involving a doctrine known as Monophysitism, had developed in the Eastern Church. This dispute pitted the Coptic Church, Egypt’s indigenous Christian body, and other Middle Eastern Christians against the Byzantine rulers.
The conflict with Byzantine rule in Egypt helped to open the way to the conquest of Egypt by an Islamic Arab in 641. Many Egyptians welcomed the Arab conquerors as liberators from foreign taxation and religious persecution.